Table 2. Summary of Major Guidelines and Recommendations for RDTs to Detect SARS-CoV-2.^*.

Guideline or Recommendation	WHO	CDC	ECDC	IDSA
Endorsement of RDTs
Antigen-based RDT	Yes	Yes	Yes	No
Molecular RDT	Yes	Yes	Yes	Yes
Testing indication
Person with symptoms of Covid-19	Yes	Yes	Yes	Yes, molecular test only
Asymptomatic person with high pretest probability of infection	Yes	Yes	Yes	Yes, molecular test only
Screening in asymptomatic person with low pretest probability of infection	Yes†	Yes	Yes, if population prevalence ≥10%	Yes, molecular test only
Specific situation
Repeat serial RDTs after negative test, if high clinical suspicion	Yes†	Yes	Yes	No
Confirmatory testing recommended	No	No	Yes‡	Yes§
Timing for testing an asymptomatic person after an exposure	NC	5–7 days	2–7 days	NC
Provide support for patient performing swab specimen collection	No	Yes	No	Yes
Endorse home-based RDT	No	Yes	NC	NC
Case registration, isolation, and contact tracing	Yes	Yes	Yes	NC

^*ECDC denotes European Center for Disease Prevention and Control, IDSA Infectious Diseases Society of America, NC no comment in guideline document, RDT rapid diagnostic test, and SARS-CoV-2 severe acute respiratory syndrome coronavirus 2.

^†The WHO endorses antigen-based RDTs for serial screening strategies when there is a suspected outbreak of Covid-19 in congregate settings, including schools, nursing homes, and health care facilities, and emphasizes that these tests will be most reliable in settings with ongoing transmission, which they define as a test positivity rate of 5% or higher.²²

^‡The ECDC recommends confirmation of all antigen-based RDTs with either a laboratory-based nucleic acid amplification test (NAAT) or a second different antigen-based RDT.

^§The IDSA recommends confirmation of negative antigen-based RDTs with a laboratory-based NAAT in symptomatic patients who have a high clinical pretest probability of infection.